Create new curl class to handle a single url (instead of the multi-curl class I had). This allows the curl's callback to check for a failure (like a human-check) and handle it.
Create new agent to download and parse a single url. Right now, it's a bit of a clumsy mess, with insufficient error handling and now unit tests. Call it a POC (heh; POS) that we'll re-write from the bottom up.